High-quality graphene/Cu composite materials obtained through centrifugal processing

The in-situ growth of graphene on substrates with high specific surface areas, such as metallic powders, is regarded as a critical strategy to address challenges associated with non-free-standing graphene films and to enable the transformation of graphene from two-dimensional to three-dimensional (3D) architectures. However, the controllable synthesis of few-layer graphene nanosheets remains challenging due to factors including non-uniform distribution of the carbon source, unstable mass transfer during high-temperature growth, and the difficulty in forming long-range ordered thermal conduction pathways within graphene. Herein, we report an efficient strategy for fabricating graphene-like nanosheet (GNs)/Cu composites involving centrifugal screening of high-quality carbon sources with strong interfacial bonding to Cu, followed by concentration modulation to achieve a stable and controlled supply of carbon precursors. Subsequently, spark plasma sintering is employed to construct graphene with a 3D interconnected network architecture. Notably, the composite carbonized from centrifugally screened sucrose at a concentration of 1 g/30 mL exhibits a thermal conductivity of 451 W/(m·K), surpassing that of pure Cu processed under identical conditions by 16.5%. Furthermore, the composite displays a tensile strength of 313 MPa, representing a 42.3% enhancement over pure Cu. The findings underscore that high-speed centrifugal screening facilitates the selective retention of high-quality carbon sources with strong interfacial bonding, thereby providing a viable pathway for the synergistic enhancement of the overall performance of Cu-based composites. • High-speed centrifugal screening technology enables the selective retention of high-quality carbon precursors with strong interfacial bonding, yielding high quality graphene. • The introduction of solid carbon sources into copper powder, coupled with uniform pre-dispersion, can effectively mitigate issues such as inhomogeneous carbon source distribution and unstable mass transport during high-temperature growth. • The fabrication of graphene/copper composites via powder metallurgy has successfully constructed a three-dimensional graphene network. • Graphene hinders dislocation slip and contributes to the tensile work of the composite through a pull-out mechanism, leading to a significant enhancement in tensile strength.